This invention relates generally to filter devices and more particularly to devices which ensure that the position which multiple types of filter cartridges are positioned in are not altered. Presently, compressed fluid systems are used to provide compressed breathing air to be used in such applications as fire fighting or underwater diving. There are typically one or more compressed fluid systems to provide breathing air for small dive shops or for a single fire departments, except for the larger demand areas which may require more. The process required to compress fluid into the compressed fluid system also compresses whatever moistures and impurities may be contained in the air. It is highly desirable to remove as many of these impurities which are present in the original air as possible prior to or during compression of the air to limit the impurities breathed by the user, as well as restricting damage which may be done to the tank by accumulated moisture and impurities over an extended period. To accomplish this purification, filter cartridges are incorporated in the compressed fluid purification systems.
In the present systems, more than one filter cartridge may be arranged in series. Each filter cartridge contains filtering materials depending on what that specific filter is intended to remove. For this reason, adjacent tanks often contain different materials to perform different functions. For example, in present purification systems, the initial filters often remove moisture from the air while the later filters often remove the impurities. Placing the correct filter in the correct order tends to prolong the life and increase the effectiveness of the impurity removing filters.
In present filtration systems, the configuration of filter cartridges for the different filters are identical. In practise, often the cartridges are often placed in the incorrect locations resulting in a less than ideal filtering configuration. It is highly desirable to produce a configuration whereby the filter cartridges can fit only in their correct location. In this manner, the filter cartridge life may be extended while the filter process quality is improved.
The foregoing illustrates limitations known to exist in present filtering systems involving multiple filter cartridges. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.